1. Field of the Invention
The present invention relates generally to the field of cable connectors. More specifically, the present invention relates to a sled used in a modular plug for terminating electric wires within a cable, such as twisted pairs terminated at an RJ-type plug.
2. Description of the Related Art
In the telecommunications industry, modular plug type connectors, such as RJ-type connectors, are commonly used to connect customer premise equipment (CPE), such as telephones and/or computers, to a jack on a wall outlet or another piece of CPE. These modular plugs are typically used to terminate twisted pair cabling or twisted pair cordage, collectively referred to as a twisted pair cable.
Termination of a twisted pair cable poses unique assembly problems for the skilled technician. For example, terminating four twisted pairs by means of an existing modular plug requires the following steps: First, the cable or cord jacket must be stripped to access the enclosed conductors. Next, because the conductors in a conductor pair are generally twisted around one another, the cord strand must be removed and the conductors oriented to align with the required interface. For some standardized plugs, aligning the conductors also involves separating the conductors in at least one of the pairs and routing these over or under conductors from other pairs, while orienting all the conductors in a side-by-side plane, thus, the orientation process can result in various conductors of different pairs crossing over each other, thereby inducing crosstalk among the several conductor pairs.
Crosstalk is defined as the cross coupling of electromagnetic energy between adjacent conductor pairs in the same cable bundle or jacket. Crosstalk can be categorized in one of two forms: Near End Crosstalk, commonly referred to as NEXT, is the most significant because the high energy signal from an adjacent conductor can induce relatively significant crosstalk into an attenuated receiver signal. The other form is Far End Crosstalk or FEXT. FEXT is typically less of an issue because the far end interfering signal is attenuated as it traverses the loop. Because the jack springs, conductors and the plug terminals or contacts near the jack springs are generally quite close to, and exposed to, one another in a communication plug, control of crosstalk is a paramount consideration in any plug design.
Unfortunately, crosstalk in a communication plug cannot be merely eliminated. Older plugs had relative high NEXT levels and also the NEXT level varied greatly in a plug-to-plug comparison. The drawbacks of older plug designs are discussed more fully in U.S. Pat. No. 6,056,586 of Lin, issued May 2, 2000, the disclosure of which is herein incorporated by reference.
Modern jacks are engineered to generate a certain amount of compensating crosstalk to counter the crosstalk produced in the plug. Accordingly, modern communication plugs should be designed to “optimize” rather than to minimize crosstalk. The term “optimize” is meant to convey that the crosstalk induced in a plug is controlled, and hence constant as compared to any other plug. Hence, if the induced NEXT in a plug is predictable, the jack can be accurately designed to compensate for that anticipated level of NEXT induced in the plug.
Accordingly, there exists an ongoing need for a modular plug for terminating a twisted pair cable, that provides a straightforward interface between the conductors in the cable and the plug terminals, that is easy to assembly, and that has substantially unvarying electrical characteristics from plug to plug.
Steps toward achieving these goals are disclosed in U.S. Pat. Nos. 6,250,949 and 7,425,159 of Lin, issued Jun. 26, 2001 and Sep. 16, 2008, respectively, the disclosures of which are herein incorporated by reference. U.S. Pat. Nos. 6,250,949 and 7,425,159 provide a modular plug that can be easily assembled by a technician. The plug includes a conductor organizing sled, which controls the routing and placement of the twisted pairs of conductors inside the plug. The conductor organizing sled helps to ensure that the lengths of the individual conductors, and relative placements of the individual conductors, inside the plug is relatively consistent from plug to plug. Hence, the plug designs disclosed in U.S. Pat. Nos. 6,250,949 and 7,425,159 help to “optimize” the NEXT, so that the NEXT of the plug can be effectively reduced by a NEXT compensation scheme within a jack.
Such a plug has been well accepted in the industry and vastly employed. However, there is always a trend toward faster transmission speeds and a further reduction of NEXT, such that future plug/jack combinations will need to “optimize” NEXT within the plug even further, as performance standards increase (such as the minimum performance characteristics defined by future CAT standards).